Method of preventing oxidation of metal

ABSTRACT

A method of preventing oxidation of a metal is disclosed. The method includes: placing a metal piece in a vacuum container; injecting hydrogen gas into the vacuum container; heating the metal piece placed in the vacuum container up to 200° C.; cooling the vacuum container and discharging the hydrogen gas; removing the metal piece from the vacuum container; and placing the metal piece in an oxygen-containing environment. An additional inorganic film or organic film is not needed to be used for blocking the oxygen from contacting the metal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of preventing oxidation of a metal.

2. The Prior Arts

A conventional method of treating an oxide on a surface of a metal includes the prevention of oxidation, and the removal of rust after the metal is oxidized.

The method for preventing oxidation includes a surface treatment or a surface processing, and by which the physical, mechanical, and chemical properties of the surface of the metal or non-metal such as plastic can be changed so that the metal or non-metal becomes more corrosion-resistant, wear-resistant and heat-resistant, and has longer use life, and also, the surface properties of the metal or non-metal can be improved in order to increase, for example, the electrical conductivity or the surface gloss of the metal or non-metal. In the surface treatment, a protective film will be formed on the surface of the metal or plastic. The protective film can be an inorganic film or an organic film. The inorganic film includes metal, glass, and ceramic materials, and a chemical synthesis film obtained by using the phosphorylation or anodization process. The chemical synthesis film is a film containing the metal by using the chemical or electrochemical process. The organic film includes paint, resin, paraffin, ointment, rubber, and asphalt materials, etc. However, each of the protective films has its specific properties and uses. For example, the ceramic films are heat-resistant and acid-resistant, but brittle so that they will break on impact. Moreover, a protective compact metal oxide (such as aluminum oxide) film can be formed on the surface of the metal by using the anodization process.

The method of removal of the rust includes: removing the oxide on a surface of a metal; acid washing the metal by using an acid liquid; and planarizing the surface of the metal so as to prevent the oxygen and the moisture from retaining in the rough surface of the metal; and carrying out a surface treatment.

SUMMARY OF THE INVENTION

The objective of the present invention is to provide a method of preventing oxidation of a metal. By using the method of the present invention, an additional inorganic film or organic film is not needed to be used for blocking the oxygen; the electrical conductivity is increased by 0.5˜2%; and in a process for packaging of a copper wire, a Class 1 clean room is not necessary, and the nitrogen gas for retarding the oxidation is not needed to be used during the wire bonding process, and the step of acid washing is not needed to be carried out such that an object of an environmental protection can be achieved.

In order to achieve the objective and solve the problems in the prior art, the present invention provides a method of preventing oxidation of a metal, which comprises: placing a metal piece in a vacuum container; injecting hydrogen gas into the vacuum container; heating the metal piece placed in the vacuum container up to 200° C.; cooling the vacuum container and discharging the hydrogen gas; removing the metal piece from the vacuum container; and placing the metal piece in an oxygen-containing environment.

In one aspect of the present invention, a metal oxide is placed in an enclosed vacuum chamber or container. Then, the hydrogen gas is injected into the enclosed vacuum container, and then the entire vacuum container is heated up to 180˜200° C. (in a non-combustion state). The oxide on the surface of the metal will be removed. After the surface of the metal is treated by above process, the metal is placed in an oxygen-containing environment. A compact metal oxide film will be formed on the surface of the metal. The compact metal oxide can block the oxygen from contacting the metal, and thereby the surface of the metal will not be further oxidized again. The gold wire, silver wire, copper wire, iron wire, and aluminum wire can be treated by using the method of the present invention so as to form a compact metal oxide film on the surface of the metal to prevent the metal from further oxidizing.

The advantages of the present invention are listed below. An additional inorganic film or organic film is not needed to be used for blocking the oxygen. The electrical conductivity is increased by 0.5˜2%. In a process for packaging of a copper wire, a Class 1 clean room is not necessary, and the nitrogen gas for retarding the oxidation is not needed to be used during the wire bonding process, and the step of acid washing is not needed to be carried out such that an object of an environmental protection can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be apparent to those skilled in the art by reading the following detailed description of a preferred embodiment thereof, with reference to the attached drawings, in which:

FIG. 1 is a flowchart illustrating a method of preventing oxidation of a metal according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The accompanying drawing is included to provide a further understanding of the invention, and is incorporated in and constituted a part of this specification. The drawing illustrates an embodiment of the invention and, together with the description, serves to explain the principles of the invention.

FIG. 1 is a flowchart illustrating a method of preventing oxidation of a metal according to an embodiment of the present invention. Please referring to FIG. 1, a metal piece is placed in a vacuum container (S10), and then hydrogen gas is injected into the vacuum container (S20), and subsequently the entire vacuum container is heated up to 200° C. (S30), and then the vacuum container is cooled down and the hydrogen gas is discharged (S40), and thereafter the metal piece is removed from the vacuum container (S50), and then the metal piece is placed in an oxygen-containing environment (S60).

In one embodiment, a metal oxide is placed in an enclosed vacuum chamber or container, wherein the metal can be, for example, gold, silver, copper, iron, or aluminum. Then, the hydrogen gas is injected into the enclosed vacuum container, and then the entire vacuum container is heated up to 180˜200° C. (in a non-combustion state). The oxide on the surface of the metal will be removed. The chemical equations are shown below:

M(O₂)+H₂→M+H₂O (at high temperature)

M(O₂) is a metal oxide, and M is a metal.

For example, at high temperature, the copper oxide and the iron oxide on the metal surface are respectively reduced to the pure copper and the pure iron. The chemical equations are shown below:

CuO +H₂→Cu+H₂O

Fe₂O₃+3H₂→2Fe+3H₂O

After the surface of the metal is treated by above process, the pure metal is placed in an oxygen-containing environment. A compact metal oxide will be formed on the surface of the metal. The compact metal oxide can block the oxygen from reaching the metal, and thereby the surface of the metal will not be oxidized again. The gold wire, silver wire, copper wire, iron wire, and aluminum wire can be treated by using the method of the present invention so as to form a compact metal oxide film on the surface of the metal to prevent the metal from further oxidizing.

The advantages of the present invention are listed below. An additional inorganic film or organic film is not needed to be used for blocking the oxygen. The electrical conductivity is increased by 0.5˜2%. The method of the present invention can be applied to the semiconductor, the printed circuit board, the wire cable, and any other industrial process for preventing oxidation of a metal. For example, in a process for packaging of a copper wire, a Class 1 clean room is not necessary, and the nitrogen gas for retarding the oxidation is not needed to be used during the wire bonding process, and the step of acid washing is not needed to be carried out such that an object of an environmental protection can be achieved.

Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims. 

What is claimed is:
 1. A method of preventing oxidation of a metal, comprising: placing a metal piece in a vacuum container; injecting hydrogen gas into the vacuum container; heating the metal piece placed in the vacuum container up to 200° C.; cooling the vacuum container and discharging the hydrogen gas; removing the metal piece from the vacuum container; and placing the metal piece in an oxygen-containing environment. 